He charted private helicopters and jets, stayed in five-star country retreats and treated friends to shopping sprees at Harrods – but all the time he was living in a tiny bedsit in Sussex.

The jobless 53-year-old – described by detectives as like a character from hit BBC show Hustle – enjoyed a luxury lifestyle for four months, spending the $1 million savings of a Caribbean woman he had conned.

People assumed he could afford the lavish spending because he was believed to be the boss of a Swiss-based investment firm called Quantum Management, with 20 years’ experience at investment bank Goldman Sachs.

In fact he spent time at his bedsit in Wynnstay, Oakhill Park, Burgess Hill, trawling the internet for information on fraud.

The woman, who has not been named, was so convinced by Stewart’s charm she handed over the nest egg for it to be invested in the fictitious firm.

Four-month spree

He blew it all in just four months between August 2010 and January 2011.

He bought his girlfriend a £31,000 watch and treated himself to a £54,000 Mercedes CLK.

Stewart, who has previous, similar convictions, regularly flew to five-star hotels, including the Chewton Glen in Hampshire, where he would collect staff, charter a helicopter to City Airport in London and take them shopping in Harrods.

Detective Inspector Mick Richards, of Sussex Police’s fraud squad, said: “He adopted the personality of a multi-millionaire. In four months he blew more than £600,000. It’s unbelievable and very unusual.”

Stewart, described by police as a “master of disguise”, was so |impressive when he first appeared at magistrates’ court charged with fraud counts that staff thought he was a barrister.

Yesterday (November 19) at the Old Bailey in London he admitted one count of fraud by false representation.

Speaking after the case, DI Richards described the crime as being like something from Hustle.

He said: “He is very plausible, so, so believable – it’s almost unbelievable.

“He is a master of disguise. Even at the point of prosecution he was deceiving people. He was living in a fantasy world and was so grandiose.

“It was yachts, helicopters and fancy hotels.”

DI Richards, working with DC Nicola Balkham, described how Stewart contacted his victim online and built up her trust.

She told him she had lost her father in an avalanche and he remembered this – telling her he too had lost his wife in a skiing accident, which was a lie.

He then claimed to have lived in the same Swiss village where she went to boarding school.

Series of lies

DI Richards said: “He remembered every single detail. There were many coincidences and it was all baloney.

“And this girl he cheated is no slouch. She is bright and intelligent.”

DI Richards said after a time – and with Stewart “grooming” her – she agreed to invest her entire life savings, – $1m, about £640,000 – in his company”.

When she visited him in the UK he treated her to a lavish time– but it was actually her money he was spending.

DI Richards said the woman Stewart fleeced, the director of an estate agent in the Turks and Caicos Islands in the Caribbean, had been left heartbroken by his deceit and is now receiving counselling.

He said: “She had fallen head over heels for him. Her daughter looked up to him.”

She was not in court to hear Stewart plead guilty but may be in the UK when he is sentenced on December 19.